View of distant terrain shows crack on promontory (9)
I believe the answer is:
moonscape
'view of distant terrain' is the definition.
'moonscape' can be an answer for 'terrain' (I have seen 'Rocky terrain' mean 'moonscape' so perhaps 'terrain' could also mean 'moonscape'). I am unsure of the 'view of distant' bit.
'crack on promontory' is the wordplay.
'crack on' becomes 'moons' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'promontory' becomes 'cape' (both can mean a headland).
'moons'+'cape'='MOONSCAPE'
'shows' is the link.
Can you help me to learn more?
(Other definitions for moonscape that I've seen before include "Barren terrain" , "Unearthly vista" , "desolate scene" , "Rocky terrain" , "piece for the night?" .)